codebase-mapper

A knowledge base and set of writing rules for producing a readable guide to an unfamiliar codebase.

In plain words
What is it for?
Use it with codebase-mapper agents to document architecture, features, workflows, data, setup, configuration, and open questions.
Why use it?
It helps turn source-code analysis into explanations for developers who are new to the project, instead of raw technical notes.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/acaprino/daodan/codebase-mapper
Any agent
npx skills add acaprino/daodan --skill codebase-mapper
Clone the repo
git clone --depth 1 https://github.com/acaprino/daodan

Made for: Claude Code, Codex.

Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,216 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00105 $0.01216
Opus 5 $0.00053 $0.00608
Sonnet 5 $0.00021 $0.00243
Haiku 4.5 $0.00011 $0.00122

Measured 2d ago against content hash 6268650fc49f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codebase-mapper scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

exports/claude/plugins/codebase-mapper/skills/codebase-mapper/SKILL.md · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codebase Mapper Knowledge Base

Purpose

Generate a human-readable project guide for unfamiliar codebases. Output is narrative, didactic material - not technical dumps or AI-oriented analysis. Target audience: a smart colleague on their first day.

Output Structure

All output goes to .codebase-map/ in the project root:

.codebase-map/
  INDEX.md                    # Entry point with navigable summary
  00-executive-summary.md     # Plain-language summary for anyone (non-technical)
  01-overview.md              # What is this project, who is it for
  02-features.md              # Functional capabilities
  03-tech-stack.md            # Technologies and dependencies
  04-architecture.md          # How code is organized, layers, components
  05-workflows.md             # Main user/system flows with diagrams
  06-data-model.md            # Data structures, entities, relationships
  07-getting-started.md       # Where to start working, key files, dev setup
  08-open-questions.md        # Gaps, unknowns, things to ask the team
  09-project-anatomy.md       # Config files, env vars, scripts, directory tree
  10-configuration-guide.md   # Configuration recipes, operations, troubleshooting
  11-glossary.md              # Domain and technical glossary (plain definitions)
  _internal/
    context-brief.md          # Phase 1 exploration output (internal reference)
    interconnect.md           # Phase 1b structured map: contracts, invariants, domain rules (optional)

Core Principles

Tone

  • Narrative, conversational, didactic
  • Write for the audience in the Project Profile (see references/audience-adaptation.md); default to a smart colleague on their first day when no profile exists
  • Progressive disclosure: big picture first, then details
  • Honest about gaps - never fabricate or speculate

Content Rules

  • Every technical term gets a brief inline explanation on first use
  • File paths always included - reference actual code paths for every claim
  • Diagrams inline - Mermaid blocks embedded in documents, not separate files
  • No AI boilerplate: no "In this document we will...", no "Let's dive in", no trailing summaries

Read the full file on GitHub · 97 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 97 lines · 105 tokens per session scan A 6268650fc49f

Subscribe to this mod's changes

codebase-mapper is a skill published in the GitHub repository acaprino/daodan (8 stars, last pushed 6d ago), licensed MIT. It adds 105 tokens to every session and 1,216 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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